Do not calculate composition bounds until IME requests.

content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java

Index: content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java b/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
index c52b32457b7907883dd501925ab411e3f2c5b903..7d38b13cef3510ce90afc0536df548056c49a402 100644
--- a/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
+++ b/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
@@ -193,7 +193,7 @@ public class ImeAdapter {
                 mLastSelectionStart, mLastSelectionEnd, outAttrs));
         if (DEBUG_LOGS) Log.w(TAG, "onCreateInputConnection: " + mInputConnection);
         if (mCursorAnchorInfoController != null) {
-            mCursorAnchorInfoController.resetMonitoringState();
+            onRequestCursorUpdates(0 /* disable any cursor update */);

[yosin_UTC9, 2016/07/06 02:02:01]

How about
const int kDisableAnyCursorUpdate = 0;
onRequrestCursorUpdate(kDisplayAnyCursorUpdate);

[Seigo Nonaka, 2016/07/06 03:25:56]

Done.

         }
         return mInputConnection;
     }
@@ -661,6 +661,9 @@ public class ImeAdapter {
      * Notified when IME requested Chrome to change the cursor update mode.
      */
     public boolean onRequestCursorUpdates(int cursorUpdateMode) {
+        if (mNativeImeAdapterAndroid != 0) {

[yosin_UTC9, 2016/07/06 02:02:01]

nit: Not need to have curly bracket.

[Seigo Nonaka, 2016/07/06 03:25:56]

Thanks, but presubmit warns if I removed curly braces.
Looks like we can drop curly braces only when it is single-line statement.

+            nativeRequestCursorUpdate(mNativeImeAdapterAndroid, cursorUpdateMode);
+        }
         if (mCursorAnchorInfoController == null) return false;
         return mCursorAnchorInfoController.onRequestCursorUpdates(cursorUpdateMode,
                 mViewEmbedder.getAttachedView());
@@ -750,5 +753,6 @@ public class ImeAdapter {
             int before, int after);
     private native void nativeResetImeAdapter(long nativeImeAdapterAndroid);
     private native boolean nativeRequestTextInputStateUpdate(long nativeImeAdapterAndroid);
+    private native void nativeRequestCursorUpdate(long nativeImeAdapterAndroid, int mode);
     private native boolean nativeIsImeThreadEnabled(long nativeImeAdapterAndroid);
 }